Q2 Postmastery's Email Delivery Benchmark

Second Global Email Delivery Benchmark Report Summary

This second quarterly report evaluates email delivery performance from April to June 2024, with comparisons to the prior assessment.

An expanded dataset means that the benchmark offers an even clearer snapshot of MBP email delivery performance. It provides a baseline for senders to compare and improve their email delivery metrics. Postmastery plans to release these benchmarks regularly, with the next report expected in late 2024.

Key Metrics

• Delivery Rate: Most ESPs continue to perform exceptionally well, with delivery rates consistently exceeding 99%. Seznam.cz remains nearly perfect, exemplifying top-tier delivery efficiency.
• Bounce Rate: Mimecast still has the highest bounce rate among the providers at 4.41%. This rate has not changed since the previous report, indicating persistent challenges in their email delivery processes.
• Deferred Rate: Although Mimecast's deferred rate has improved significantly from 29.71% to 10.39%, it continues to lead with the highest deferred rates among ESPs. This suggests ongoing issues with server responsiveness or mail server delays.
• Average Delivery Time: The range of delivery times shows variability among providers. Seznam.cz continues to lead with an exceptionally fast average delivery time of just 33 seconds. In contrast, Comcast and Orange show the longest times, indicating potential inefficiencies with over 15 and 20 minutes respectively.

Detailed Insights

• Bounce Rate Analysis: Continues with visual charts detailing bounce rates for major providers like Google, Outlook.com, Yahoo, and Office 365, illustrating trends and areas for improvement.
• Deferred Rate Analysis: Highlights significant variances among Mailbox Providers (MBPs), reflecting different handling of emails during high-volume periods.
• Average Delivery Time: Shows detailed performance across different time buckets, providing insights into the efficiency of mail delivery systems across providers.
• Common SMTP Errors: Lists updated common errors for major providers, helping in the diagnosis and rectification of delivery issues.
• New Google Error Codes: Introduces additional Google-specific error codes and deferrals, providing deeper insights into common delivery challenges and how to address them.